The present invention relates generally to ultrasonic diagnostic systems, and, more particularly, to identifying a volume of interest, or a sub-volume, within a volume rendered image.
Ultrasonic transducers and imaging systems have been available for quite some time and are particularly useful for non-invasive medical diagnostic imaging. Ultrasonic transducers are typically formed of either piezoelectric elements or of micro-machined ultrasonic transducer (MUT) elements. When used in transmit mode, the transducer elements are excited by an electrical pulse and in response, emit ultrasonic energy. When used in receive mode, acoustic energy impinging on the transducer elements is converted to a receive signal and delivered to processing circuitry associated with the transducer.
The transducer is typically connected to an ultrasound imaging system that includes processing electronics, one or more input devices and a suitable display on which the ultrasound image is viewed. The processing electronics typically include a transmit beamformer that is responsible for developing an appropriate transmit pulse for each transducer element, a receive beamformer that is responsible for processing the receive signal received from each transducer element, and additional processing circuitry that receives the data from the receive beamformer and converts the data so that an ultrasound image may be rendered on a display.
An ultrasonic transducer is typically combined with associated electronics in a housing. The assembly is typically referred to as an ultrasonic probe. Typically, ultrasonic probes are classified as either one-dimensional (1D) probes having a single element wide array of elements, or two-dimensional (2D) probes having a multiple element wide array. Furthermore, a probe referred to as a xe2x80x9cbi-planexe2x80x9d probe includes two orthogonally positioned 1D arrays that may or may not intersect. A relatively new 2D probe, referred to as a xe2x80x9cmatrix probexe2x80x9d includes transducer elements arranged in two dimensions where each element is individually controllable, resulting in an ultrasound probe the scan lines of which can be electronically steered in two dimensions. Each dimension of a matrix probe can be thought of as a stack of contiguous linear arrays.
A matrix probe can comprise either a xe2x80x9cfully sampledxe2x80x9d or a xe2x80x9csparsely sampledxe2x80x9d aperture. In a fully sampled aperture, every transducer element is individually addressable and controllable, and all elements are contiguous. In a sparsely sampled aperture, a subset of the physical set of transducer elements is addressed and controlled, or equivalently, there is a pattern of physical gaps between some elements such that they are not all contiguous. Sparsely sampled 2D arrays allow for fewer system connections (fewer channels) while still achieving distribution of the acoustic elements in two dimensions. However, a significant drawback of sparse 2D arrays is the loss of ability to control scan beam shape.
Regardless of the type of transducer probe and related electronics, medical ultrasound imaging systems generally project a cursor onto the display of the ultrasound image. The cursor may take the form of a point, an xe2x80x9cX,xe2x80x9d a cross-hair, or other type of indicator that a user of the ultrasound system can use to identify specific portions of the ultrasound image to, for example, emphasize an anatomic feature of interest for the purpose of system control or visualization. Ultrasound imaging systems that can render a three-dimensional volume of an image generally use a cursor that is presented as reference lines drawn on scan planes of the image or drawn through a rendered volume, such as the scan planes 4 and 6 of the image 2 of FIG. 1. Alternatively, another example of a conventional cursor for a three-dimensional volume rendering is a wire-frame shape, such as a trapezoidal or frustum shape superimposed on a rendered volume. Such a cursor is illustrated in FIG. 2 in which a two-dimensional cursor 14 in the form of a wire-frame trapezoid is superimposed on a rendered image 12. These cursors aid the user of the ultrasound imaging system in selecting the planes of the three-dimensional data that are to be displayed.
Unfortunately, existing three-dimensional rendering systems lack the ability to allow a user to identify a volume of interest within the rendered image, or select a sub-volume of the three-dimensional data to display. For example, the superimposed two-dimensional cursor does not allow the user to adequately indicate the volume, or sub-volume of interest.
Therefore, it would be desirable to have an ultrasound imaging system capable of allowing a user to conveniently identify a three-dimensional volume of interest in a rendered image using a cursor that allows a user to view the data selected in a volume of interest while scanning or while viewing a previously scanned image.
Embodiments of the invention include a system and method for presenting a volume cursor on an ultrasound image, and include a system and method for identifying a volume of interest to a user of a three dimensional (3D) ultrasound imaging system. In one embodiment, the invention collects acoustic data, develops a three dimensional (3D) ultrasound image from the collected acoustic data, renders the ultrasound image on a display, modifies selected portions of the acoustic data, and displays the modified acoustic data in the form of a highlighted region on the rendered ultrasound image, wherein the highlighted region defines an included volume.